Conventionally, use of a data warehouse (DWH) has attracted attention at the time of associating data input to a core system, which is “detailed data” having detailed contents such as a detailed statement or slip, with analysis of various business purposes. Generally, the analysis of detailed data by using a data warehouse is realized by a data warehouse stores therein the detailed data, a data mart stores therein an aggregate result obtained by aggregating the detailed data stored in the data warehouse for a desired analysis purpose, and a front-end application for analyzing the aggregate result stored in the data mart.
A method of aggregating detailed data is explained with specific examples. For example, Japanese Patent No. 3476349 discloses such a method that a data processor aggregates detailed data including common items (for example, “sales period”, “product name”, “sales area”, “sales data”, and the like) for each element corresponding to an analysis purpose (for example, ‘Tokyo’) based on hierarchical structure information of each item (for example, ‘computer’ and ‘personal computer’ relating to “product name”, and ‘nationwide’, ‘Kanto’, or ‘Tokyo’ relating to “sales area”), and stores the aggregated data in a database beforehand. Further, for example, Japanese Laid-open Patent Publication No. 2001-28005 discloses such a method that a data warehouse server aggregates detailed data including common items (for example, “product code”, “customer code” and the like) for each master item corresponding to the analysis purposes based on master item information of each item (for example, ‘manufacturer category’ and ‘product name’ relating to “product code”, “customer name” and ‘personnel code’ relating to “customer code”, and the like), and stores the aggregated data in a database beforehand.
In the conventional technique, detailed data respectively input to a plurality of core systems cannot be aggregated easily and flexibly corresponding to analysis purposes, and the detailed data, which is the basis of aggregated data, cannot be easily tracked.
That is, to aggregate the detailed data respectively input to the core systems, which includes items defined for each system (or event), corresponding to the analysis purposes according to the methods disclosed in Japanese Patent No. 3476349 and Japanese Laid-open Patent Publication No. 2001-28005, two-stage aggregation needs to be performed for each analysis purpose, such that aggregation of detailed data is performed for a group of detailed data including the common items (for example, detailed data input to the same system) for each element (or master item) corresponding to the analysis purpose, and the detailed data aggregated for each group is further aggregated for a plurality of groups.
Therefore, simple aggregation cannot be performed corresponding to the analysis purposes. Further, to perform aggregation corresponding to a new analysis purpose different from a presupposed purpose, the two-stage aggregation needs to be performed again. Therefore, there is a problem that flexible aggregation cannot be performed. Further, when the two-stage aggregation is performed for each analysis purpose, the detailed data, which is the basis of the aggregated data, cannot be easily tracked, because an intermediate aggregate result is not generally stored.